What is the name of Georgia O'Keeffe's series featuring pelvic bones?

Georgia O'Keeffe's series featuring pelvic bones is called the Pelvis Series.

O'Keeffe began painting bones after finding animal remains in the New Mexico landscape. The Pelvis Series focuses on the openings and curved structures of pelvic bones, often placing them against intense blue skies. These paintings transformed a natural object associated with death and dryness into a subject of light, space, and movement.

The bones were not simply illustrations of anatomy. O'Keeffe cropped and enlarged them, using their forms as visual structures in much the same way she used flower petals, shells, and architectural details. This approach made the objects recognizable while also pushing them toward abstraction.

Her bone paintings are sometimes confused with her cow-skull works. Both groups belong to her New Mexico period, but the Pelvis Series is specifically identified by pelvic bones and their distinctive openings.